A Virus Found In Lakes May Be Literally Changing The Way People Think

A group of scientists from Johns Hopkins and the University of
Nebraska accidentally discovered something unexpected and
potentially disturbing.

While conducting a separate experiment, the scientists
learned that a virus was living in the mouths and
throats of a good portion of the people in the study, a virus
that the researchers didn't think was capable of infecting
humans. Worse still, it seemed to be slowing some of the
subjects' mental abilities, especially their ability to process
visual information.

Surprising to researchers was that a microscopic organism that we
thought could infect only algae — plants — was living in about
40% of the small number of people tested.

For the rest of us, the bigger surprise may be that this virus
could join the ranks of microorganisms that live inside and on
us, changing the way we think.

In a way, this is less crazy than it seems. Microscopic organisms
live all over people and have all kinds of effects on our health,
brain, and behavior.

There are far more microorganisms in and on a "person" than there
are "human cells." Along with a few pounds of bacteria —
trillions of microbes — an even larger number
of viruses live in and on the human body. And we know that
some of these other creatures may change the way we think and
feel, and even the way we interact with others.

"We're really just starting to find out what some of these agents
that we're carrying around might actually do," study co-author
Dr. Robert Yolken, a professor at The Johns Hopkins University
School of Medicine,
told Healthline.

But they also swabbed the throats of the participants and did a
genetic analysis of what was there. In 14 of the 33 people, they
found genes from a virus that until now had never been found in
living people (researchers had found it once before in someone's
brain during an autopsy, but they didn't know whether it had been
there when the person was alive).

The virus, called ATCV-1, is a chlorovirus, a family of viruses
that infect plants. This one affects algae — that green stuff
that grows on water — in lakes all over the world. But as far as
researchers knew before this, viruses like this very rarely cross
from one kingdom like plants to another, like animals. And even
when they do, it's more likely that they would go from plants to
some type of invertebrate, not all the way to a complex animal
like a human.

Here's the most interesting part (for most of us): Because the
original study included cognitive tests, the scientists compared
the data and saw that people with the virus living in their
throats processed visual information about 10% slower than people
without the virus — and this difference could not be explained by
other factors like age, sex, race, socioeconomic status,
education, place of birth, or smoking status.

The specific visual information tests in which a difference was
shown included things like drawing a line that connected numbers
in sequence that had been scattered on a page. People with the
virus also seemed to have a shorter attention span.

To check if this group was somehow different from the general
population, the team checked another 59 people for the virus. Out
of the final 92, it was present in 40, about the same rate as in
the initial, smaller group.

To investigate whether the virus might be the cause of that
change in visual processing and attention, the researchers then
injected mice with the same virus.

Lost?Wikipedia/Rasbak

Six weeks later, the group of mice with ATCV-1
took about 10% longer to navigate a maze, and they also spent
about 20% less time exploring new environments.

The infected mice also showed more than 1,000 gene changes in the
parts of the brain that are usually considered essential for
memory and learning. The researchers could observe these gene
changes in mice because they analyzed the mice before and after
they were infected with the virus. This shows some of the effects
the virus could have on people, but we don't know that humans
would show the same changes — and it would be unethical to
conduct the same experiment on people.

Don't Go In The Water?

While this study presents some new and fascinating information,
it isn't nearly comprehensive enough to say what it all means.

"The thing that's different about what we found is that [the
virus] is something that we wouldn't have suspected would
actually have any effect on humans or animals," Yolken told
Healthline.

The whole group of people tested was from Baltimore, so we don't
know how common this virus is in the rest of the world — or even
in the rest of Baltimore, as 92 people is still a small number.
And while the information from the mice is interesting, there's
no way to say that genes in human brains necessarily change the
same way.

And even then, this is a very small effect — and just one of many
brain and behavioral changes that may be caused by the trillions
of creatures that live in and on us. Others that we know about
make people
more or less social and may be connected to
mental-health issues like
depression and
anxiety, all of which cause cognitive changes.

Still, something microscopic that we didn't even know existed in
humans is changing the way some of us think and see. That's
pretty crazy.

"There's more and more studies showing that microorganisms in
your body have a bigger influence than anything anyone would have
predicted," the paper's senior author, James Van Etten, a
University of Nebraska-Lincoln plant pathologist, told
Healthline.